Cognitive dysfunction in isolated brainstem stroke: a neuropsychological and SPECT study.

In a prospective series of patients with brainstem stroke (n=73) of the Durban Stroke Data Bank (n=752), five patients with first-ever, isolated brainstem stroke were studied neuropsychologically and with single-photon-emission computed tomographic (SPECT) scanning. Magnetic resonance brain scanning showed four pontine infarcts and one midbrain infarct without accompanying diencephalic or cerebral convexity lesions. Frontal (n=5) and parietal (n=5) hypoperfusion was detected by SPECT scanning and comparison in terms of mean counts made to five age-matched controls with a significant P value of .01 and .02, respectively. Neuro-psychological testing showed a frontal system syndrome in all five patients and parietal lobe signs in two. Excellent medical recovery ensued in four of the five patients and a moderately good recovery in one as judged by the Canadian Neurological Scale, Barthel Index, and Rankin Scale. The three relatively young patients in this series were unable to resume their former employment. This was attributed to a significant frontal system syndrome. Brainstem stroke may cause significant cognitive impairment best delineated by formal neuropsychological evaluation, and SPECT scanning may be more sensitive than structural neuroimaging techniques in this setting.